RU2040116C1 - Device for measuring and regulation of signal delay time in circuits for transmission tonal frequency channel - Google Patents

Abstract

FIELD: measuring devices. SUBSTANCE: device provides measuring absolute values of packet transfer time of direct and reverse directions of transmission of tonal frequency channel. In addition device equalizes delay time of signal transmission circuits. Device has clock, transmission unit, four time delay regulation units, two modulators, two demodulators, six commutation units, two sweeping frequency oscillators, comparison unit, decoder, two clipping circuits, two units for computing packet transfer time, two units for computing phase-frequency response, two units for selection of recording time, two units for preliminary signal processing, two generators of counting pulses, receiving unit, encoder, transmission circuits. EFFECT: increased precision of measuring and regulation of delay time in signal transmission circuits. 8 dwg

Description

 The invention relates to a measurement technique for electrically conductive communication and can be used to measure and control the delay time of the transmission and reception channels of the PM channel, designed to transmit accurate time signals.

 A device for measuring the delay time of signals in a channel for receiving a tonal frequency channel is known, which allows one to measure and adjust the delay time of a channel for receiving multi-channel transmission systems. Measurement and regulation of the delay time of the reception path allows to obtain a higher accuracy of the transmission of time signals compared to the PM channels, in which such regulation of the paths of the transmission of time signals (APSV) was not carried out.

 The path delay time is understood as the time elapsed from the moment the leading (trailing) edge of the pulse signal was input at the input of the path under study to the moment of recording the controlled pulse front at the channel output. The lag time, in contrast to the group transit time (HWP), which is understood as the first derivative of the phase-frequency characteristic with respect to the circular frequency, is determined by both frequency characteristics of the frequency response and phase response paths. As follows from the definition, the delay time refers to the discrete signal transmission channel; therefore, it depends both on the parameters of the PM channel and on the properties of the secondary compaction equipment.

 A device for measuring the delay time of signals in a transmission channel of a tonal frequency channel is provided, which comprises a pulse generator, a first delay time control unit and a modulator, the output of which is an input of a transmission channel of a tone frequency channel, an extension cord connected between the transmission path and the reception channel of the tone frequency channel serially connected demodulator, the input of which is combined with the input of the level gauge, the second delay time control unit and h stotomer, a second input coupled to an output of the pulse generator and the input device connected to the outlet channel tone.

 This device allows you to measure and adjust the delay time of the transmission path with the adjusted path of receiving the PM channel. A feature of the prototype is that in the process of measuring and adjusting the delay time, the individual and group equipment of one terminal station is included in the measured path. Whereas the transmission of accurate time signals is carried out via PM channels formed by individual and group equipment of various terminal and intermediate stations. Naturally, the use of elements controlled and regulated as part of various circuits in the transmission path of accurate time signals can be the cause of an additional error.

 Thus, the disadvantage of this device is the inaccuracy of measuring the delay time and the possibility of an additional error in the operation of the exact time transmission system due to differences in the group signal propagation time (GWP) in the forward and reverse directions of transmission of the linear path of multichannel communication equipment.

 The purpose of the invention is to increase the accuracy of measuring and regulating the delay time of signal transmission paths by measuring the absolute values of the GWP of the forward and reverse directions of transmission of the PM channel and aligning the delay time of signal transmission paths.

 This is achieved by the fact that a time source is introduced into the device, the output of which is connected to the first input of the APSV transmission unit, the output and second input of which are connected respectively to the input of the first and output of the second delay time control units, the switching unit, the decoder, the comparison unit, and the unit are connected in series delay control, the first output of which is connected to the second input of the first delay time control unit, and the second output is connected to the first input of the second delay time control unit the second input of which is connected to the output of the demodulator, the second input of which is connected to the output of the modulator, the second input is connected to the output of the oscillating frequency generator, and the output to the input of the transmission channel of the PM channel direction, the third switching unit, the signal preprocessing unit, the registration timing selection unit, the phase response calculator, the GWP calculation unit and the GWP latch, the output of which is connected to the second input, are connected in series m of the comparison unit, the output of the signal preprocessing unit is connected to the second input of the phase response calculating unit, the third input of which and the second input of the recording moment selection unit are connected respectively to the first and second outputs of the counting pulse generator, the output of the PM channel transmission path in the forward direction is connected to series-connected fourth switching unit, second demodulator, third delay time control unit, APSV reception unit, fourth delay time control unit, fifth b a switching window, a second modulator and a sixth switching unit, the second input of which is connected to the output of the second oscillating frequency generator, and the output is connected to the input of the PM channel transmission path in the opposite direction, the output of which through the third switch is connected to the input of the first demodulator, the second preliminary block is connected in series signal processing, the second unit for selecting the moment of registration, the second unit for calculating the phase response, the second unit for calculating the GWP, the second latch for the GWP and an encoder, the output of which is connected to the second input of the switching unit, the second output of the fourth switching unit is connected to the input of the second signal preprocessing unit, the output of which is connected to the second input of the second phase response block, the third input of which and the second input of the second recording moment selection unit are connected respectively to the first and second outputs of the second counting generator pulses.

 The introduction of new units with appropriate connections allows the measurement of absolute GWP values for the average frequency of the PM channel, transfer the measured GWP value of the forward direction to the transmission side, compare the GBP values of the forward and reverse directions, and make the corresponding changes in the delay adjustment blocks on the transmission side , which provides increased accuracy of the transmission of time signals.

 It follows that the proposed device should provide the following three modes of operation: measuring HWP, installing HWP, transmitting time signals.

 In FIG. 1 shows a general block diagram of a device; figure 2 is a structural diagram of the device in the mode of "measuring the GWP"; figure 3 structural diagram of the device in the mode of "installation of hot water"; figure 4 is a structural diagram of the device in the mode of "transmission of time signals"; figure 5 shows the plot of the time dependences of the test signal: and the signal voltage at the input of the PM channel; b signal voltage at the output of the PM channel; in the waveform at the output of the signal preprocessing unit; Fig.7 block diagram of the calculation of the phase response; in Fig.8 block diagram of the calculation of the GWP.

 A device for measuring and adjusting the delay time of signal transmission paths on the PM channel contains, on the transmission side, a time source (clock) 1, APSV transmission unit 2, delay time adjustment unit 3, modulator 4, switching unit 5, delay time adjustment unit 6, block 7 delay control, oscillating frequency generator (GCF) 8, comparison unit 9, decoder 10, switching unit 11, demodulator 12, switching unit 13, GWP lock 14, GWP calculation unit 15, phase response calculation block 16, registration timing selection block 17, block 18 p signal pre-processing 18 and counting pulse generator 10, on the receiving side a switching unit 20, a demodulator 21, a delay time control unit 22, a signal preprocessing unit 23, a registration timing selection unit 24, an APSV reception unit 25, a phase response calculating unit 26, a generator 27 counting pulses, switching unit 28, modulator 29, switching unit 30, delay time adjustment unit 31, GWP calculation unit 32, oscillating frequency generator 33, encoder 34, GWP lock 35, as well as transmission paths of the PM channel in forward 36 and reverse 37 nap ION.

 The time source 1 is connected to a series-connected transmission unit APSV 2, block 3 control the delay time, a modulator 4 and a switching unit 5, the output of which is connected to the input of the transmission path 36, and the second input is connected to GKCh 8. The output of the transmission path 37 is connected to series-connected the switching unit 13, the demodulator 12, the switching unit 11, the decoder 10, the comparison unit 9 and the delay control unit 7, the first output of which is connected to the second input of the unit 3, and the second output to the input of the control unit 6 building, the second input of which is connected to the second output of the switching unit 11, and the output is connected to the second input of the unit 2. The second output of the switching unit 13 is connected to the signal processing unit 18, the registration timing selection unit 17, the phase response calculator 16, the calculation unit GWP 15 and the GWP latch 14, the output of which is connected to the second input of the comparison unit 9.

 The output of block 18 is connected to the second input of block 16, the third input of which is connected to the output of the generator 19, the second output of which is connected to the second input of block 17. The output of the transmission path 36 is connected to series-connected switching unit 20, demodulator 21, delay time control unit 22, APSV receiving unit 25, lag time control unit 31, switching unit 30, modulator 29 and switching unit 28, the output of which is connected to the input of the transmission path 37, and the second input is connected to the circuit-breaker 33. To the second output of the switching unit 20 are connected serially connected unit 23 pretreatment signal selection unit 24, the registration of 24 PFC calculating unit 26, calculation unit 32 GWP GWP retainer 35 and the encoder 34, the output of which is connected to the second input of unit 30.

 The output of block 23 is connected to the second input of the phase response block, the third input of which is connected to the output of the generator 27, the second output of which is connected to the second input of the block 24.

 The GWP calculation block 15 (32) (see Fig. 8) contains a conversion unit 15.1, a calculation block 15.2, a clamp 15.3 for the cutoff frequency, a clamp 15.4 for the previous cutoff frequency, a calculator for the difference in cutoff frequencies 15.5, an adder 15.6, a divisor by two 15.7 and medium frequency indicator 15.8.

 The PFC calculation block 16 (26) (see Fig. 7) contains a packet selection block 16.1, a packet duration counter 16.2, a packet duration lock 16.3, a calculation block 16.4, a phase difference lock 16.5, a control block 16.6, a database block 16.7.

 The signal preprocessing unit 18 (24) (see Fig. 6) contains an input device 18.1, a driver 18.2, a differentiating chain 18.3, a bridge rectifier 18.4.

 The device operates as follows.

 The mode of "measurement of GWP" (see figure 2). In the considered mode, the frequency-modulated oscillations from the oscillating frequency generator 8 are fed to the input of the PM channel of the forward direction of transmission 36, the output of which the phase-shifted oscillations in accordance with the phase-frequency characteristic arrive at signal preprocessing unit 23. From the output of block 23, the signal is sent in parallel to the input of the block 24 select the moment of registration and the input of the block 26 calculating the phase response curve, and the second inputs of the blocks 24 and 26 are supplied with counting pulses from the generator 27 of the counting pulses.

The differential phase response (Δθ _km ) and the boundary frequencies (f _{gr. 1} , f _gr . ₂ ), calculated in the calculation unit of the phase response 26, are transmitted to the calculation unit GWP 32.

 The GWP values of the forward direction of transmission of the PM channel 36, calculated in block 32, are transferred to the GWP latch 35, where they are stored and stored until they are transferred to the transmission side. A similar interaction of elements characterizes the device when measuring the HWP of the reverse direction of transmission of the PM 37 channel; the oscillating frequency generator 33 transmits a frequency-modulated signal through a channel 37, from the output of which through the switching unit 13 the signal is supplied to the pre-processing unit 18, and then as a result of sequential processing in the registration timing selection block 17, the phase response calculation block 16, and the GWP calculation block 15, the GWP value of the reverse transfer direction of the PM channel 37 is stored and stored in the GWP latch 14.

 As a meter of the phase difference phase response, which then calculates the absolute value of the GWP, a known device for measuring the phase response is used.

 The principles of operation of this device for measuring the phase response is based on controlling the rate of change of the frequency of the test signal at the input and output of the channel. As a test signal, frequency-modulated oscillations with a linear law of frequency change generated by the oscillating frequency generator (8 and 27) are used.

1

как для одного пери- ода, так и для группы, включающей М им- пульсов, Δθ_кмM

1

Определение длительности интервалов Δτ_км и Δ t_км, вычисление перепада фазы Δθ_км и граничных частот (f_гр.1, f_гр.2) осуществляется в блоке вычисления ФЧХ 16 (26).The rate of change of the frequency of the test signal at the input of the channel is not advisable to control, since it is determined by the well-known law of operation of the oscillating frequency generator (8 and 27). The frequency-modulated signal coming from the PM channel in the electrical signal processing unit 18 (26) is converted into a sequence of short pulses that are apart from each other by the current time Δτ _k . Comparison of the corresponding intervals at the input (Δ t _to ) and at the output (Δτ _to ) of the channel allows you to determine the phase difference Δθ _to

1

both for one period and for a group including M pulses, Δθ _km M

1

The determination of the duration of the intervals Δτ _km and Δ t _km , the calculation of the phase difference Δθ _km and the boundary frequencies (f _{gr. 1} , f _gr . ₂ ) is carried out in the block for calculating the phase response 16 (26).

Вычисленные абсолютные значения группового времени в блоках 15 и 32 передаются соответственно в фиксатор ГВП 14 или фиксатор ГВП 35, где запоминаются до момента перехода к следующему режиму работы устройства.The calculated values of Δθ _km and f _{gr. 1} , f _gr . ₂ are transmitted from blocks 16 or 26 to the GWP calculation unit 15 (32), where the absolute value of the GWP of the reverse transmission direction (t _{group B-A} ) of the PM 37 channel is calculated or the direct direction of transmission (t _GRA-B ) of the PM 36 channel. When moving from the phase difference Δθ _km to the absolute value of the group time, the formula is used
t _gr

The calculated absolute values of the group time in blocks 15 and 32 are transmitted respectively to the GWP latch 14 or the GWP latch 35, where they are memorized until the next mode of operation of the device.

 The mode of "installation of GWP" (see figure 3).

The operation of the device in the "GWP installation" mode consists in the fact that the numerical value of the GWP absolute value of the forward direction of transmission of the PM channel 36 t _{group AB is} supplied to the encoder 34 from the GWP latch 35, where it is encoded and transmitted using the reception modulator 29 via channel PM 37. From the channel output, the signal on the transmission side enters the transmission demodulator 12, is received and fed to the decoder 10, from the output of which the signal goes to the first input of the comparison unit 9. The absolute value of the GWP 14 receives the absolute value G P reverse transmission direction _{gr.B t-A,} measured in the previous mode.

 In block 9, the absolute value of the GWP of the forward and reverse transmission directions is compared, on the basis of which a difference signal is generated, which is supplied to the delay control unit 7. Depending on the sign of the difference signal, the delay control unit 7 makes corresponding changes to the delay adjustment unit 3 or the delay adjustment unit 6. Thus, the positions of the regulators of blocks 3 or 6 are refined.

 The mode "transmission of time signals" (see figure 4).

 The operation of the device in the "time signal transmission" mode consists in transmitting signals from the time source 1 on the PM 36 channel in the forward direction, receiving signals and processing them in the receiving part of the APSV 25 on the receiving side, transmitting the processed signals in the opposite direction of the PM 37 channel, receiving them on the transmission side and refinement of the time signals in the transmitting part of the APSV.

 Consider the interaction of the elements of the device in this mode. The time source 1 sends a uniform sequence of pulses to the APSV 2 transmission unit, where, according to them, time information signals are generated, including the so-called “date”, numerical time values in the form of binary code sequences, as well as second and minute pulses. From the output of the APSV 2 transmission unit, information signals pass through the delay adjustment unit 3, in which, depending on the position of the regulator, the signals are shifted in time, after which they are transmitted to the transmission modulator 4.

 In transmission modulator 4, the binary pulses are converted into phase-modulated oscillations, which are transmitted through the switching unit 5 to the input of the PM channel 36. From the output of the PM 36 channel, the signal through the switching unit 20 is fed to the receiving demodulator 21, where binary sequences of pulses are generated from the phase-modulated oscillations, which after mixing in time in the block 22 adjust the delay arrive at the block receiving APSV 25.

 The information signal received by the APSV 25 receiving unit, firstly, provides for fixing and indication of time instants, and, secondly, it allows generating a signal, which is then transmitted to the transmission side to the APSV 2 transmission block.

 The signal generated by the APSV 25 receiving unit through the delay time adjustment unit 31 and the switching unit 30 is fed to the receiving modulator 29, where it is converted to a phase-modulated oscillation, which is fed through the switching unit 28 to the input of the channel of the reverse direction 37.

 From the output of the PM 37 channel, the phase-modulated oscillations through the switching unit 13 are transmitted to the transmission demodulator 12, where they are converted into a binary pulse sequence, which, through the switching unit 11, the second delay adjustment unit 6 is supplied to the APSV 2 transmission unit.

 We will clarify the operation of the device in the mode of measuring HWP.

Let us dwell, first of all, on the form of the test signal in the mode of GWP measurement, for which the frequency-modulated oscillation with the linear law of frequency variation is selected. Then the signal at the input and output of the PM channel can be written as
U _in A ₁ sin 2 πα t ² ;
U _o A ₂ sin [2 πατ ² -b (ω))] where b (ω) is the phase response of the PM channel.

When controlling the rate of change of the signal frequency, we take into account the duration of the half-periods of the test signal. On figa, b shows the time plot of the voltage of the signal at the input and output of the channel, where the corresponding half-periods are designated Δt _to and Δτ _to . However, it is more expedient to control not the durations of individual half-periods, but the duration of a group including M half-periods, which are shown in FIGS. 5a, b by Δt _k and Δτ _km , respectively.

 In the physical implementation of control elements for the duration of half-periods, the signal is first subjected to special processing, including the formation of rectangular pulses, differentiation and rectification. All this is done in the blocks of electrical signal processing 18 and 24, at the output of which the signal can be represented in the form of figure 5, c.

 The circuit of the signal preprocessing unit 18 (24) is shown in FIG. 6.

 Input device 18.1 provides a 600-ohm load for the PM channel; driver 18.2 implements the signal in the form of a sequence of rectangular pulses, from which bipolar pointed pulses are formed in the differentiating chain 18.3. Using a bridge rectifier 18.4 at the output of the electric signal processing unit 18, pointed unipolar pulses are obtained (see Fig. 5c), which allows you to clearly record the moments of the transition of the test signal through zero (see Fig. 5, b). Next, the test signal is supplied to the blocks for selecting the moment of registration 17 (24) and to the calculation unit for the phase response 16 (26).

Determination of the registration is performed via a customized counter included in this block and sets the time of occurrence of the signal portion with a frequency f 1923 Hz, which corresponds to the half-period duration Δτ _to 13,100 microseconds. This moment is fixed by the tuned counter, when it counts 13100 pulses from the counting pulse generator 19 or 27, and a "reference point" signal will be sent for the phase response blocks 16 and 26.

 The circuit block for calculating the phase response 16 (26) is shown in Fig.7.

 The control unit 16.6, receiving from the block 17 the signal "reference", includes the blocks 16.1, 16.4, 16.7 and initiates the operation of all elements of the block 16.

Block 16.1 sets the time limits of the packet, and in block 16.2 determines the duration of the packet Δτ _km by counting the number of counting pulses from the generator 19. The value of the duration of the packet is fixed in block 16.3, and then transferred to the calculation block 16.4. To the second information input of block 16.4 from the database block 16.7, the value of the duration of the signal packet at the input Δ t _km is transmitted.

1

рассчитывается перепад фазы ФЧХ Δθ_км, значение которого фиксируется в блоке 16.5.In block 16.4 according to the formula Δθ _km M

1

the phase-phase difference Δθ _{km is} calculated, the value of which is fixed in block 16.5.

 Note that the value of M is determined by the rate of change of the frequency of the test signal. For a speed of α 1000 Hz / s, the most convenient value is M 100.

The magnitude of the differential phase response from block 16.5 and the corresponding values of the boundary frequencies (f _{gr. 1} , f _gr . ₂ ) from block 16.7 are transferred further to the calculation unit GWP 15 (32).

где b(ω) ФЧХ канала ТЧ;
ω круговая частота.The group time of signal transmission in accordance with the definition given earlier when considering the basic concepts used is expressed by the formula
t _gr

where b (ω) the phase response of the PM channel;
ω circular frequency.

Последняя формула представлена в виде произведения двух сомножителей, каждое из которых рассчитывается в элементах блока вычисления ГВП 15 и 32, структурная схема которого изображена на фиг.8.This formula for finite phase differences and frequency intervals can be represented as
t _gr

The last formula is presented in the form of the product of two factors, each of which is calculated in the elements of the calculation unit GWP 15 and 32, the structural diagram of which is shown in Fig. 8.

 The calculated value of the GWP usually refers to the average frequency of the interval, i.e.

Блок пересчета 15.1 фактически реали- зует вычисление

подготав- ливая тем самым значение, которое будучи деленное на разность граничных частот, дает величину ГВП это выполняется в расчетном блоке 15.2.f _cf

Recalculation block 15.1 actually implements the calculation

thereby preparing a value that, being divided by the difference of the boundary frequencies, gives the value of the GWP, this is done in calculation block 15.2.

 Measurement of the GWP of the forward and reverse directions of transmission of the PM channel allows you to specify the adjustment of the delay time of the paths and thereby improves the accuracy of the transmission of time signals in comparison with the PM channel in which such adjustment was not carried out.

Claims (1)

 DEVICE FOR MEASURING AND REGULATING THE TIME OF THE DELAY OF SIGNALS IN THE TRANSMISSIONS OF THE TRANSMISSION OF THE CHANNEL OF THE FREQUENCY FREQUENCY, comprising the first block of the delay time control and the first modulator connected in series, the second delay time control unit and the first demodulator, characterized by the fact that the time source is connected to it signals of the time source, the second input of which is connected to the output of the second delay time control unit, and the output is connected to the first Ode to the first delay time control unit, the first oscillating frequency generator and the first switching unit are connected in series, the second input of which is connected to the output of the first modulator, and the output is the input of the forward channel transmission path, the second switching unit is connected in series, the input of which is the signal input from the path transmitting the channel of the reverse direction, the first block of signal preprocessing, the first block of the choice of the moment of registration, the first phase-frequency calculation unit x characteristics, the first group transit time calculation unit, the first latch, the comparison unit and the delay control unit, one output of which is connected to the first input of the delay time regulation unit and the other to the second input of the first delay time adjustment unit, connected in series to the third switching unit, whose input connected to the second output of the second switching unit through the first demodulator, and a decoder, the output of which is connected to the second input of the comparison unit, the second output of the third unit switching is connected to the second input of the second delay time control unit, the first counter pulse generator, the outputs of which are connected respectively to the second inputs of the first unit, select the moment of registration and the first phase-frequency characteristic calculation unit, the third input of which is connected to the output of the first signal preprocessing unit, connected in series the fourth switching unit, the input of which is the signal input from the output of the transmission path of the forward channel, the second demodulator, a third delay time control unit, a time source signal reception unit, a fourth delay time control unit, a fifth switching unit, a second modulator and a sixth switching unit, the output of which is an input of the reverse channel transmission path, and the second input is connected to the output of the introduced second oscillating frequency generator connected in series to a second signal preprocessing unit, the input of which is connected to the output of the fourth switching unit, a second register selection unit a second phase-frequency characteristic calculation unit, a second group transit time calculation unit, a second latch and an encoder whose output is connected to the second input of the fifth switching unit, a second counting pulse generator whose outputs are connected respectively to the second inputs of the second registration moment selection unit and the second unit computing a phase-frequency characteristic, the third input of which is connected to the output of the second signal preprocessing unit.

Images